According to the U.S. Bureau of Labor Statistics, prices for personal computers and peripheral equipment were
6.50% lower
in 2019 versus 2017 (a $1.30 difference in value).

Between 2017 and 2019:Personal computers and peripheral equipment experienced an average inflation rate of -3.31% per year.
This rate of change indicates significant deflation.
In other words, personal computers and peripheral equipment costing $20 in the year 2017 would cost $18.70 in 2019 for an equivalent purchase.
Compared to the overall inflation rate of 1.71% during this same period, inflation for personal computers and peripheral equipment was
significantly lower.

In the year 2017: Pricing changed by -4.20%, which is
below the average yearly
change for personal computers and peripheral equipment during the 2017-2019 time period.
Compared to inflation for all items in 2017 (2.13%), inflation for personal computers and peripheral equipment was
much lower.

Price Inflation for Personal computers and peripheral equipment since 1997

Consumer Price Index, U.S. Bureau of Labor Statistics

Years with the largest changes in pricing:
1999 (-31.61%),
2001 (-28.05%),
and 2002 (-24.97%).

Buying power of $20 since 2017

Below are calculations of equivalent buying power for Personal computers and peripheral equipment, over time, for $20 beginning in 2017. Each of the amounts below is equivalent in terms of what it could buy at the time:

How to calculate the inflation rate for personal computers and peripheral equipment, 2017-2019

Start with the inflation rate formula:

CPI in 2019 / CPI in 2017* 2017 USD value = 2019 USD value

Then plug in historical CPI values from above. The CPI for Personal computers and peripheral equipment was 42.564 in the year 2017 and 39.796 in 2019:

39.796 / 42.564* $20 = $18.70

Therefore, according to U.S. Bureau of Labor Statistics, $20 in 2017 has the same "purchasing power" as $18.70 in 2019 (in the CPI category of Personal computers and peripheral equipment).

Source: U.S. Bureau of Labor Statistics began tracking the Consumer Price Index for Personal computers and peripheral equipment in 1997. In addition to personal computers and peripheral equipment, the index produces monthly data on changes in prices paid by urban consumers for a variety of goods and services.